ML20016A445

COL Docs - Draft LAR for Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements - Pre-submittal Meeting on 1/23/2020

ML20016A445
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Site:	Vogtle
Issue date:	01/16/2020
From:	NRC
To:	NRC/NRR/DNRL
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Download: ML20016A445 (30)

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From: Rankin, Jennivine Sent: Thursday, January 16, 2020 2:54 PM To: Vogtle PEmails

Subject:

Draft LAR for Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements -

Pre-submittal meeting on 1/23/2020 Attachments: LAR-229 PSM Draft.pdf From: Santos, Cayetano Sent: Thursday, January 16, 2020 6:47 AM To: Rankin, Jennivine <Jennivine.Rankin@nrc.gov>; Patel, Chandu <Chandu.Patel@nrc.gov>

Subject:

Fwd: RE: LAR-229 PSM tentative date For Vogtle Public Meeting scheduled on 1/23/2020.

From: "Arafeh, Yasmeen N." <YNARAFEH@southernco.com>

Subject:

[External_Sender] RE: LAR-229 PSM tentative date Date: 14 January 2020 09:52 To: "Santos, Cayetano" <Cayetano.Santos@nrc.gov>

Begin Forwarded Message:

From: "Arafeh, Yasmeen N." <YNARAFEH@southernco.com>

Subject:

[External_Sender] RE: LAR-229 PSM tentative date Date: 14 January 2020 09:52 To: "Santos, Cayetano" <Cayetano.Santos@nrc.gov>

Hi Tanny, attached is the draft for LAR-229. Could you please forward this to the appropriate staff, and let us know a good date for a PSM? SNC is currently targeting 1/23, but I understand if the staff would need more time to review beforehand.

Best, Yasmeen Arafeh Nuclear Development, Licensing Work: (205)992-7190 ynarafeh@southernco.com From: Santos, Cayetano <Cayetano.Santos@nrc.gov>

Sent: Monday, January 6, 2020 10:43 AM To: Arafeh, Yasmeen N. <YNARAFEH@southernco.com>

Cc: Rankin, Jennivine <Jennivine.Rankin@nrc.gov>

Subject:

RE: LAR-229 PSM tentative date

EXTERNAL MAIL: Caution Opening Links or Files

Yasmeen, Happy New Year.

I guess it would depend on when you could provide a draft LAR to us. We would need enough time to ensure the right branches are represented and have enough time to review it before the meeting. When do you think you could provide it to us?

Tanny From: Arafeh, Yasmeen N. <YNARAFEH@southernco.com>

Sent: Monday, January 06, 2020 10:59 AM To: Santos, Cayetano <Cayetano.Santos@nrc.gov>

Subject:

[External_Sender] LAR-229 PSM tentative date Hi Tanny, SNC would like to hold a PSM for LAR-229, Change to separation criteria between Nuclear Island and Turbine building structural elements, on 1/23/20 via teleconference to support a LAR submittal on 1/31/20. Could you please let me know if the staff could be available on 1/23/20, or if wed need to choose another date? Thanks so much.

Best, Yasmeen Arafeh Nuclear Development, Licensing Work: (205)992-7190 ynarafeh@southernco.com

Hearing Identifier: Vogtle_COL_Docs_Public Email Number: 522 Mail Envelope Properties (BY5PR09MB48184CD8A9CA295A3C9FF82398360)

Subject:

Draft LAR for Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements -

Pre-submittal meeting on 1/23/2020 Sent Date: 1/16/2020 2:54:07 PM Received Date: 1/16/2020 2:54:12 PM From: Rankin, Jennivine Created By: Jennivine.Rankin@nrc.gov Recipients:

"Vogtle PEmails" <Vogtle.PEmails@nrc.gov>

Tracking Status: None Post Office: BY5PR09MB4818.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 2837 1/16/2020 2:54:12 PM LAR-229 PSM Draft.pdf 1012057 image001.png 1703 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Southern Nuclear Operating Company ND-20-XXXX Enclosure 1 T

Vogtle Electric Generating Plant (VEGP)

(VEG Unit 3 AF Request Unit 3 Auxiliary est for License Amendment:

icense Amendm y Building Wall 11 Seismic (LAR-20 (LAR 0-00 0

Seism Gap Requirements (LAR-20-001)

R D

(Enclosure 1 consists of 14 pages, including this cover page.)

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001)

Table of Contents

1.

SUMMARY

DESCRIPTION

2. COMBINED DETAILED DESCRIPTION

3. TECHNICAL EVALUATION

4. REGULATORY EVALUATION 4.1. Applicable Regulatory Requirements/Criteria 4.2. Precedent 4.3. Significant Hazards Consideration 4.4. Conclusions

5. ENVIRONMENTAL CONSIDERATIONS T

6. REFERENCES AF R

D Page 2 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001)

Pursuant to 10 CFR 52.98(c) and in accordance with 10 CFR 50.90, Southern Nuclear Operating Company (SNC) hereby requests an amendment to Combined License (COL) No. NPF-91 for Vogtle Electric Generating Plant (VEGP) Unit 3.

1.

SUMMARY

DESCRIPTION The proposed changes would revise VEGP Unit 3 COL Appendix C (and VEGP Unit 3 plant-specific Tier 1) Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC), and corresponding UFSAR Tier 2* and Tier 2 information applicable only to VEGP Unit 3, to modify the seismic gap requirements above grade between the nuclear island and the adjacent annex building/turbine building between Column n Lines Li I and J from El. 141 through El. 154 in the licensing basis to accommodate e construction constru con as-built localized nonconformances at VEGP Unit 3.

rom the Update The requested amendment requires departures from Updated Final Safety Analysis T

Report (UFSAR) Tier 2 Appendix 2.5E Section 5.2 and rmati a Subsection rmation, and UFSAR Tier 2* Subsection 3.8.5.1 information, Unit 3 COL Appendix C (and VEGP Unitt 3 plant-specific pla -specific plant Table 3.3-6. This enclosure requests approval ction 3.7.2 ch 3.7.2.8.1 information, hat involve changes that cha to the VEGP specif Tier 1) information in ITAAC val of the license amendment am necessary to D

ssions of changes implement these changes. All discussions change to VEGP VEG Unit 3 COL Appendix C are also understood to impact the e corresponding VEGP V Unit 3 plant-specific Tier 1 information.

2.

R DETAILED DESCRIPTION AF ected Design Background and Affected As described in the and plant-specific he VEGP sign Functions Functio EGP Units 3 and 4 Updated ific Tier 1 and C include the containment (the steel s structure) and the shield and auxiliary auxi aux integrat int buildings are structurally integrated U Final Safety Analysis Report (UFSAR)

Appendix C Section 3.3, the nuclear island structures COL Appe containment vessel and the containment internal buildings. The containment, shield and auxiliary on a common basemat which is embedded below the ant grade level.

finished plant level. The level T nuclear island structures provide protection for the a

safety-related equipment against the consequences of either a postulated internal or external event. The nuc nuclear island structures are designed to withstand the effects of natural phenomena a ssuch as hurricanes, floods, tornados, tsunamis, and earthquakes without loss of capability to perform safety functions. The nuclear island structures are designed to withstand the effects of postulated internal events such as fires and flooding without loss of capability to perform safety functions. The nuclear island structures are classified as seismic Category I and are designed to withstand the safe shutdown earthquake (SSE) loads.

As described in UFSAR Subsection 3.7.2.8.1, the portion of the annex building adjacent to the nuclear island is a structural steel and reinforced concrete seismic Category II structure, designed not to collapse in SSE.

As stated in UFSAR Subsection 3.7.8.2.3, the turbine building is a braced steel frame structure with the first bay (adjacent to the nuclear island) classified as seismic Category II and with the rest of the bays classified as non-seismic.

Page 3 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001)

As described in UFSAR Subsection 3.8.5.1, the turbine building and annex building are structurally separated from the nuclear island structures by a 3-inch minimum gap above grade. This provides space to prevent interaction between the nuclear island structures and the adjacent seismic Category II structures during a seismic event. The maximum relative seismic displacement between the roof of the nuclear island and the turbine and annex buildings is less than 2 inches. This results in a clearance (gap) between buildings greater than 1 inch during a seismic event. Therefore, there are no interactions between the nuclear island and adjacent seismic Category II buildings during a seismic event.

Detailed Description of Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements In order to facilitate the construction of the nuclear island d and adjacent ad buildings, and to maintain the seismic gap in compliance with the licensing sing basis, ba it is proposed to modify the seismic gap requirements above grade between n the nuclear nuclea island and the adjacent annex building/turbine building between Column n Lines I and J from El. 141 through El. 154 in the licensing basis to accommodate mmod mmodate uctio a construction as-built localized nonconformances at VEGP Unit 3. Specifically, cally, the minimum gap b between the nuclear island and the annex building/turbine building ding ng (in a region regio between Column Lines I and J from El. 141 through El. 154) is 2-3/16 16 inches hes base based on the as-built configuration at VEGP Unit 3.

Currently, the requirement in the e licensing nsing basis for the minimum m gap between the nuclear island and annex building/turbine rbine building lding is 3 inches, inches as specified in COL Appendix C ITAAC No. 3.3.00.13, UFSAR SAR Appendix 2.5E 2. Se Section 5.2, and UFSAR Subsections 3.7.2.8.1 and 3.8.5.1. UFSARFSAR Subsection 3.8.5.1 3 requires that a minimum 1-inch gap be maintained between the he nuclear island and ann a annex building/turbine building considering the displacements of the he buildings during the SSE SS events. The purpose of the licensing basis requirements is s to prevent revent interactio ti interaction between the nuclear island and annex ne building during SSE building/turbine S ev events.

osed change The proposed changes s are to rel relax the minimum gap requirements above grade in the VEGP Unitt 3 licensing basisbasi between be the nuclear island and the annex building/turbine ween C building between Co lumn Column n Lin L

Lines I and J from El. 141 through El. 154 from a 3-inch gap to a minimum gap p of 2-1/16 2-1/1 inches in COL Appendix C ITAAC No. 3.3.00.13, UFSAR 2-Appendix 2.5E Sectionction 5.2, and UFSAR Subsections 3.7.2.8.1 and 3.8.5.1, to bound the nonconforming measured minimum gap of 2-3/16 inches in this localized area. Due to the proposed less than 1-inch reduction in the minimum gap above grade at the area of the localized nonconformance, the maximum relative displacement between the roof of the nuclear island and the annex building/turbine building described in UFSAR Subsection 3.8.5.1 remains unchanged (i.e., max relative displacement less than 2-inches). The maximum relative seismic displacement between the nuclear island and the annex building/turbine building is such that the reduction of the seismic gap requirements does not affect the requirement to maintain a 1-inch minimum gap during SSE events in UFSAR Subsection 3.8.5.1.

The proposed change does not impact any additional COL Appendix C descriptions or Figures because the minimum gap between the nuclear island and the annex building/turbine building is not specified or dimensioned elsewhere in COL Appendix C text or figures. The proposed changes do not affect the gap below grade between the Page 4 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001) nuclear island and the annex building/turbine building as defined in the licensing basis.

The proposed changes do not affect the displacements in the east-west direction between the nuclear island and the annex building in the licensing basis. Additionally, the proposed changes do not affect the gap above grade between the nuclear island and the annex building/turbine building outside the area of the localized nonconformance. In other words, the proposed change only applies to the minimum gap between the nuclear island and the annex building/turbine building between Column Lines I and J from El. 141 through El.

154 at VEGP Unit 3.

Description of Changes to Current Licensing Basis Documents COL Appendix C (and plant-specific Tier 1) Changes:

The following changes to VEGP Unit 3 COL Appendix ix C (and VEGP Unit U 3 plant-specific Tier 1) are proposed:

1. VEGP Unit 3 COL Appendix C (and VEGP T

GP Unit ria, ITAAC No. 3.3.00.13 Acceptance Criteria, ations horizontal clearance between elevations U 3 plant-specific ia, is revised to ns 141-0 141-t add ecific Tier add ; exc 141-0 and 154 T 1) Table 3.3-6, except that the minimum 154-0 between structural 2-1/16 inches.

is 2-1/16 inches AF

2. VEGP Unit 3 COL Appendix nd the nuclear elements of the annex building and lear island is eptance Criteria, is revised ITAAC No. 3.3.00.13 Acceptance etween elevations 141-0 horizontal clearance between 141 ine building and the nuclear elements of the turbine pla betw between x C (and VEGP Unitt 3 plant-specific p

column lines I and J is Tier 1) Table 3.3-6, revise to add ; except that the minimum and 154-0 between structural nucle island between column lines I and J

1. UFSAR Rs:

UFSAR Changes:

The following g changes changes to the he UFSAR UF AR Appendix 2.5E Section Sect applicable to VEGP Unit 3 only are proposed:

5.2 is revised to add and which is less than the D nches minimum ga 2-1/16 inches between elevations 141-0 141 section 3

2. UFSAR Subsection gap at Unit 3 between nuclear island and annex building and 154-0 between column lines I and J en elevations 141-0 and 154-0 between structural elements of the at Unit 3 between 3.7.2.8.1 is revised to add ; except that the minimum clearance annex building and the nuclear island between column lines I and J is 2-1/16 inches

3. UFSAR Subsection 3.8.5.1 Tier 2* is revised to add ; except that the minimum gap for Unit 3 between elevations 141-0 and 154-0 between column lines I and J is 2-1/16 inches

3. TECHNICAL EVALUATION The structures adjacent to the nuclear island are the annex building, the radwaste building, and the turbine building. The portion of the annex building adjacent to the nuclear island is a structural steel and reinforced concrete seismic Category II structure. The turbine building is a braced steel frame structure with the first bay (adjacent to the nuclear island) consisting of structural steel and reinforced concrete classified seismic Category II and the rest of the bays are classified as non-seismic. Seismic Category II structures are Page 5 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001) designed so that an SSE does not cause unacceptable structural failure or interaction with seismic Category I items.

AP1000 Generic Soil-Structure Interaction (SASSI) Analysis The current licensing basis, including COL Appendix C ITAAC No. 3.3.00.13, UFSAR Appendix 2.5E Section 5.2 and UFSAR Subsections 3.7.2.8.1 and 3.8.5.1, defines a minimum 3-inch gap above grade between the nuclear island and adjoining buildings. The purpose of the gap is to avoid contact between the nuclear island and seismic Category II structures (annex building/turbine building) when the buildings deflect during an SSE event. The seismic response analyses including soil structure ctur interaction between the nuclear island and the adjoining building are performed using the System for Analysis of Soil-Structure Interaction (SASSI) program. The maximum mum relative r sseismic displacement cified in UFSAR is established from the 2D SASSI analyses, as specified UFS Su Subsection 3.7.2.8.4.

operties, basemat The SASSI models consist of soil profiles and properties, basema mode models and structure models. The latest AP1000 generic 2D T

models, which include the coupled auxiliary andnd shield building stick mo ontainment vessel stick model. The SASSI internal structures stick model and steel containment astt-west and the turbine bu models also include the annex building east-west D SASSI SI analys model, containment building first bay as stick th the maximum relative analyses show that As the AP1000 Generic displacements between AF in the north-south direction, which displacement requirement; note displacement is outside the ch urbine building and seismic displacement between the turbine an the n h is less than the 2-inch 2

nuclear island is 1.04 inches 2-inc maximum relative seismic ote that this maximum north-south relative seismic e area off the localized nonconformance and bounds any acement in the nonconforming north-south relative displacement non nonconform neric SASSI analysis do ween en the nuclear island and area.

does not explicitly model the north-south a the annex building, an assessment of the R

bounding nature e of the north south disp ng was performed.

turbine building nd turbine building first bay building and displacements between the nuclear island and the performed Specifically, Speci a comparison of the stiffness of the annex ba was made to demonstrate that for the north-south buildin is much stiffer than the turbine building which confirms seismic motion, the annex building D rbine building di that the turbine ng--to ng Comparison of SSE displa displacements to-auxiliary iliary building relative displacements calculated in the generic turbine building-to-auxiliary are larger under SSE demand. Therefore, the SASSI analysiss can be used to compare to the nonconforming measured gaps.

E maximum m standard plant relative displacements between the north face of the auxiliary building and south face of the turbine building first bay measured gaps is performed and the maximum relative displacements represent building response under SSE where the nuclear island and the adjacent building will potentially be closest together.

Linear interpolation is used to estimate the relative displacements between the walls at elevations between 100 and the roof. Using linear interpolation is a conservative estimate because the base restraint of each structure will minimize rotation at the lower elevations and using a straight-line interpolation conservatively overestimates how close the building will be.

The gap between auxiliary building and annex/turbine building at locations with nonconformances during a seismic event calculated based on generic SASSI is equal to or larger than 1.32 inches which is larger than the licensing basis requirement of a 1-inch minimum gap.

Page 6 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001)

Site-Specific SASSI Analysis A site-specific 2D SASSI analysis was performed for VEGP Units 3&4 to show the acceptability of the AP1000 plant at the Vogtle site. The site-specific SASSI analysis performed for the Vogtle site includes site-specific soil properties and embedment effects, and site-specific SSE. The site-specific SASSI was performed before AP1000 plant DCD, Rev. 19 was approved and does not include the recent changes in the nuclear island (e.g.,

polar crane mass change) and adjacent buildings (e.g., change in structures of turbine building first bay). A study has since been performed to compare the deflections at the perimeter walls from the generic SASSI analysis using models including the significant building changes to those that do not include the changes. ges.. The results of the study ges confirmed that the recent changes to the building structuresres do not have significant impact ldings.

dings.

on the result of the relative displacement between buildings.

As was demonstrated for the generic SASSI analysis, nalysis, the turbine turb bui building-to-auxiliary to compare to the nonconforming measured specific relative displacements between the T building relative displacements calculated in the he e site-specific site d gaps.

gap e north face of SASSI ASSI ana gaps. Comparison of SSE o the auxiliary asured gaps is performed face of the turbine building first bay measured p auxili a

analysis can be used S maximum site-building and south and the maximum relative AF displacements represent building response and annex/turbine building at locations calculated based on the VEGP inches which is larger than gap. As such, the proposed Nuclear Island and the sponse under SSE together. The adjacent building will potentially be closest together.

SS where the nuclear island and the Th gap ons with nonconformances nonconfor GP Unit 3 site-specific site sit -specific SASSI n the licensing basis posed change to the sei SA bas requirement requ g between auxiliary building during a seismic event is equal to or larger than 1.73 of a 1-inch minimum seismic seismic gap at VEGP Unit 3 between the he annex building/turbine building between Column Lines I and J from El. 141 through El. 15454 provides sufficien sufficient separation between the nuclear island and D

adjacent seismic icc Category II b Settlement Evaluation R

In addition to the effect of SS buildings under un site specific conditions.

SSE, differential settlement of foundations may impact the gaps between the nuclear island and adjacent buildings. Therefore, differential settlement of foundations is evaluated based on the VEGP Units 3 settlement survey data collected cific settlement from the site-specific s monitoring program for potential impact on the gap between the nuclear island and adjacent buildings. The settlement monitoring program monitors the settlement of building foundations during the construction stages to verify the structural displacements due to construction loads and continues to monitor after construction is complete. The VEGP Unit 3 settlement survey data of the past few years indicates that the nuclear island basemat has deflected more in the center and less at the perimeter which would tend to cause the perimeter walls to lean towards the center of the nuclear island. Theoretically, this suggests that the nuclear island tends to tilt away from the turbine building and annex building. The survey data also indicates the foundation deflection contour of the turbine building and the annex building is uniform in the vicinity of the nuclear island, which does not result in tilt of the perimeter structures towards the nuclear island. From a practical perspective, as construction load induced settlement occurs, even if walls were to lean towards the gap, construction means and methods require that, as wall construction progresses upward, walls are installed at original design Page 7 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001) location, offsetting any minor tilt that may have occurred in the walls below, effectively minimizing building tilt induced by the short-term settlement. The long-term (consolidation) settlement is expected to be relatively small because the Vogtle site has very thick engineered compacted fill and over consolidated Blue Bluff Marl overlying the lower sand stratum. Therefore, the differential settlement does not have an adverse impact on the gaps between the nuclear island and adjacent buildings.

Conclusion Nonconforming gaps between the annex building and the auxiliary building in the north south direction and between the turbine building first bay and nd tthe auxiliary building in the north south direction are identified. The gaps between the he annex anne building and auxiliary an building are smaller and are compared to relative displacements acements calculated aceme calc in the seismic analyses performed using SASSI. The SASSI analyses ses are performed perf tto calculate relative displacements between the turbine building and d auxiliary building build in the north south comparison shows that the gap between T

direction. Because the annex building is stiffer than the turbine buildi building in i the north south direction, the results can conservatively be used for comparison to gaps measured between the annex building and auxiliary aryy building in the north south direction. The n the auxiliary building b an annex/turbine buildings and requirement.

AF at locations with nonconformances during a seismic event ccalculated based on generic SASSI is equal to or larger than 1.32 demonstrates that the nonconforming auxiliary building where the 32 inches forming ldings occur.

building and adjoining buildings occur inches. In additio oc . The results au onformances always exceeds locations with nonconformances r

auxiliar contact under SSE and the gap between auxiliary exce exc addition, review of the measured gaps ng locations are loc e maximum localized and not at the top of the um relative displacements dis between the auxiliary demonstrate that the buildings will not building and annex/turbine buildings at the 1 clearance gap licensing basis R

The proposed d change reduces the min 41 through El. 154 to 2 from El. 141 bu b

minimum gap requirement for VEGP Unit 3 between the nuclearr island and the annex building/turbine building between Column Lines I and J 2-1/16 (to bound the nonconforming measured minimum D /16--inch in this localized

/16 gap of 2-3/16-inch nuclear island proposed change ge to the V margin in a seismic e local lo d and the annex an area) which leaves at least a 1-inch gap between the building/turbine building during a seismic event. The VEGP Unit 3 gap requirement does not reduce the 1-inch gap mic event, as specified in UFSAR Subsection 3.8.5.1. The proposed change to the gap requirement does not affect the structural integrity requirements on seismic Category I structures. The safety functions of the seismic Category I structures are not impacted. The performance of the seismic Category II structures is not impacted and will not degrade the function of a seismic Category I structure, system or component.

Page 8 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001)

4. REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 10 CFR 52.98(f) requires NRC approval for any modification to, addition to, or deletion from the terms and conditions of a combined license (COL). The proposed changes involve changes to VEGP Unit 3 COL Appendix C (and VEGP Unit 3 plant-specific DCD Tier 1) Inspections, Tests, Analyses and Acceptance Criteria (ITAAC) information.

Therefore, NRC approval is required prior to making the VEGP Unit 3 plant-specific proposed changes in this License Amendment Request.

RC approval 10 CFR 52, Appendix D, Section VIII.B.6, requires prior NRC app a for departure from Tier 2* information. The proposed amendment includes ludes a departure dep from Tier 2*

information. Therefore, a License Amendment Requestest is required.

requ 10 CFR 52, Appendix D, Section VII.B.5.a allows s an applicant or licensee lice who references proposed departure involves a change to Ton, without prior NRC ap this appendix to depart from Tier 2 information, a approval, unless the o or departure from Tier 1 information, Tier 2*

ations, information, or the Technical Specifications, s, or requ requires a lice license amendment under to Tier 2 information.

10 CFR 52.97(b) requires AF Unit 3 COL Appendix C (and VEGP on. The proposed paragraphs B.5.b or B.5.c of the section. opose changes s that the Commission Commis the inspections, tests, and analyses, including includ allll perform, and the acceptance that the licensee shall accep sh change involve changes to VEGP P Unit 3 plant-specific specif DC re, NRC approval is required and Tier 2* information. Therefore, requ requi DCD Tier 1) ITAAC information prior to making the changes shall identify within the combined license those applicable to emergency planning, criteria that, if met, are necessary and R de reasonable sufficient to provide asonable assurance that the facility has been constructed and will be operated in conformity with the t licens license, the provisions of the Act, and the Commissions posed changes to the ITAAC continue to meet the requirements of the proposed egulations.. Based on the technical evaluations provided in Section 3 above, egulations rules and regulations.

2.97(b 2.97(b).

10 CFR 52.97(b).

D 10 CFR Part 50, Appendix A, General Design Criterion (GDC) 1, Quality standards and es that structures, systems, and components important to safety be records, requires d erected, and tested to quality standards commensurate with the designed, fabricated, importance of the safety functions to be performed. The nuclear island, and the portions of the annex building and turbine building first bay adjacent to the nuclear island, continue to meet the design codes committed to in the UFSAR Subsections 3.3.2.3 and 3.8. GDC 1 also requires that appropriate records of the design, fabrication, erection, and testing of structures, systems, and components (SSCs) important to safety be maintained by or under the control of the nuclear power unit licensee throughout the life of the unit. The quality assurance requirements of Appendix B to 10 CFR 50 are applied to activities affecting the nuclear island, and the portions of the annex building and turbine building first bay adjacent to the nuclear island. Thus, GDC 1 compliance is not affected by the proposed changes.

10 CFR Part 50, Appendix A, GDC 2, Design Bases for Protection Against Natural Phenomena, requires that SSCs important to safety shall be designed to withstand the Page 9 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001) effects of natural phenomena such as earthquakes, tornados, hurricanes, floods, tsunamis, and seiches without loss of capability to perform their safety functions. Seismic Category II structures, including the portions of the annex building and turbine building first bay adjacent to the nuclear island, are designed so that an SSE does not cause unacceptable structural failure or interaction with seismic Category I items. The proposed changes to the minimum 3-inch gap above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island to a minimum gap of 2-1/16 inches, which leaves at least a 1-inch gap between the nuclear island and the annex building/turbine building during a seismic event consistent with the current licensing basis, are acceptable to prevent contact between the nuclear island and these seismic Category II structures (annex building/turbine ne building) bui bu when the buildings deflect during an SSE event. The proposed changes to the e VEGP VE U Unit 3 gap requirements do not reduce the 1-inch gap margin in a seismic event, t, as identified ide in UFSAR Subsection 3.8.5.1. The proposed changes to the gap requirementsireme s do not aff irement affect the structural cture . The safety ctures integrity requirements on seismic Category I structures. afety functions ffunctio of the seismic Category I structures are not impacted. The T

rade ade the function of a seis structures is not impacted and will not degrade e performance of the sse propose changes.

Thus, GDC 2 compliance is not affected by the proposed changes seismic Category II seismic Category I SSC.

AF 10 CFR Part 50, Appendix A, GDC 4,, Environmental and Dynamic requires SSCs important to safetyy be designed to accom compatible with the environmental mental proposed changes to the minimum 3-inch accomm ccidents, including accidents, 3-inch nch gap and the portions of the annex building and tu island to a minimum gap of 2 1/16 inches do g above inclu Dyn al conditions associated ostulated a maintenance, testing, and postulated asso Effects Design Bases, accommodate the effects of and to be with normal operation, loss-of-coolant accidents. The abo grade between the nuclear island turbine building first bay adjacent to the nuclear d not involve a change to the design of the nnexx building, or turbine building. The affected portions of the annex nuclear island, annex R rbine bine building first bay adjacent building and turbine important to safety and and remain designed ear island maintain struc to the nuclear adj to the nuclear island do not house SSCs design such that the portions of the buildings adjacent structu ected by the proposed changes.

is not affected structural integrity during an SSE. Thus, GDC 4 compliance ch D

4.2 None.

4.3 eden edent Precedent Significant Hazards Consideration The proposed amendment changes COL Appendix C (and associated plant-specific Tier 1), Tier 2*, and Tier 2 material applicable only to Vogtle Electric Generating Plant (VEGP)

Unit 3, to modify the seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island.

Page 10 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001)

An evaluation to determine whether a significant hazards consideration is involved with the proposed amendment was completed by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment, as discussed below:

4.3.1 Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed changes would revise the COL and licensing basis for VEGP Unit 3 to modify the seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay ng an adjacent to the nuclear island.

The proposed changes to the gap requirement quirement do not affect affe the structural ategory I structures.

integrity requirements on seismic Category structures The safety functions T

of the seismic Category I structures es are not impacted.

impacted. The performance p of the seismic Category II structures iss not impacted and will not degrade the function ture, system, of a seismic Category I structure, system, oro component compone (SSC). The proposed AF changes do not involve a change to ysis is affected.

design or safety analysis aterial release and no rad radioactive material involved, thus the radiological rele affected..

o the design of the nuclear island, annex ding, and no SSC design building, or turbine building, fa fai desig or function is affected. No affected. The proposed accident initiating event or component failure, prop pro ously evaluated are not affected.

accidents previously aff changes do not affect any thus the probabilities of the No function used to mitigate a radioactive material release source term is releases in the accident analyses are not 4.3.2 R

the erefore, the prop Therefore, probability or consequences he probability proposed ame proposed a Does the propo amendment does not involve a significant increase in consequ cons of an accident previously evaluated.

amendment create the possibility of a new or different D kind of acciden accident from

Response

onse:: No.

onse No f any accident previously evaluated?

The proposed changes would revise the COL and licensing basis for VEGP Unit 3 to modify the seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island.

The proposed changes do not involve a change to the design of the nuclear island, annex building, or turbine building, and no SSC design or function is affected. The performance of the seismic Category II structures is not impacted and will not degrade the function of a seismic Category I SSC. The proposed changes would not introduce a new failure mode, fault or sequence of events that could result in a radioactive material release.

Therefore, the proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.

Page 11 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001) 4.3.3 Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No.

The proposed changes would revise the COL and licensing basis for VEGP Unit 3 to modify the seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island.

The proposed changes do not involve a change to the design of the nuclear island, annex building, or turbine building, and d no SSC SS design or function is affected. The performance of the seismic Category tegory II structures tegor stru is not impacted and will not degrade the function of a seismicsmic Category Cate I SSC, S and would not affect any design parameter, function or analysis. ThereThe wou would be no change to an existing design basis, design function, funct atory criterion, regulatory criter or analysis.

No safety analysis or design basiss acceptance acceptanc limit/criterion iterio is involved.

limit/criterio Therefore, the proposed amendment ment does not involve a significant reduction endment in a margin of safety.

4.4 Conclusions Based on the considerations s discussed above, (1) there the is reasonable assurance that the health and safety of the public will not be endangered enda by operation in the proposed manner, (2) such activities ivities will be conducted condu in compliance with the Commissions regulations, and (3) the issuance of the amendment ame am will not be inimical to the common defense and security urity or to the health and ssafety of the public. Therefore, it is concluded that the requested ted amendment amendmen does not involve a significant hazards consideration under the standards ds set forth in 10 CF CFR 5050.92(c), and, accordingly, a finding of no significant hazards consideration is justified.

5. ENVIRONMENTAL MENTAL CONSIDERATIONS CONSIDE CONSI The details of thee proposed propose changes are provided in Section 2 of this License Amendment Request.

The proposed amendment changes COL Appendix C (and associated plant-specific Tier 1), Tier 2*, and Tier 2 material applicable only to Vogtle Electric Generating Plant (VEGP)

Unit 3, to modify the seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island.

This review has determined the proposed changes require an amendment to the COL.

However, a review of the anticipated construction and operational effects of the requested amendment has determined the requested amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9), in that:

Page 12 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001)

(i) There is no significant hazards consideration.

As documented in Section 4.3, Significant Hazards Consideration, of this License Amendment Request, an evaluation was completed to determine whether a significant hazards consideration is involved by focusing on the three standards set forth in 10 CFR 50.92, Issuance of amendment. The Significant Hazards Consideration determined that (1) the requested amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated; (2) the requested amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated; and (3) the requested amendment does not involve a con conc significant reduction in a margin of safety. Therefore, it is concluded that the requested derat deration amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding nding of o no significant hazards consideration is justified.

(ii) of any effluents that may be released The proposed amendment changes COL T ypes or significant incr There is no significant change in the types d offs offsite.

OL Appendix pendix C (and asso increas increase in the amounts associated plant-specific Tier island.

modify the seismic gap of the annex buildingng AF p requirements requirement able only to Vogtle 1), Tier 2*, and Tier 2 material applicable Unit 3, to modify the seismic gap requirement requirements requiremen s above g and turbine building ve grade gra g

Vogt Electri equireme s abovebove g Electric Generating Plant (VEGP) grad ding and turbine building first and portions of the annex building grade between the nuclear island f bay adjacent to the nuclear The proposed changes would revise VEGP Unit 3 COL and licensing basis documents to between the nuclear island and portions building ffirst bay adjacent to the nuclear island. The R

proposed changes would introduce es are unrelated to any aspect of plant construction or operation that ce any change to t efflue anitary system effluents, biocides, sanitary effluent types (e.g., effluents containing chemicals or effluent and affect any effluent release path p

q a other effluents), or affect any plant radiological or ological effluent release quantities.

non-radiological Furthermore, the proposed changes do not or diminish the functionality of any design or operational D

features that ar aree credited wit w

with controlling the release of effluents during plant operation.

Therefore, it is concluded that the requested amendment does not involve a significant change in the types released offsite.

(iii) es or a significant increase in the amounts of any effluents that may be There is no significant increase in individual or cumulative occupational radiation exposure.

The proposed changes would revise VEGP Unit 3 COL and licensing basis documents to modify the seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island. Plant radiation zones (addressed in UFSAR Section 12.3) are not affected, and controls under 10 CFR 20 preclude a significant increase in occupational radiation exposure. Therefore, the requested amendment does not involve a significant increase in individual or cumulative occupational radiation exposure.

Page 13 of 14

ND-20-XXXX Request for License Amendment: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-001)

Based on the above review of the requested amendment, it has been determined that anticipated construction and operational effects of the requested amendment do not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in the individual or cumulative occupational radiation exposure.

Accordingly, the requested amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), an environmental impact statement or environmental assessment of the proposed exemption is not required.

6. REFERENCES None T

AF R

D Page 14 of 14

Southern Nuclear Operating Company ND-20-XXXX Enclosure 2 T

Vogtle Electric Generating Plant (VEGP)

(VEG Unit 3 AF Unit 3 Auxiliary Exemption tion Request:

y Building Wall 11 Seismic (LAR-20-001)

(LAR (LAR-20 0-00 Seism Gap Requirements R

D (Enclosure 2 consists of 7 pages, including this cover page)

ND-20-XXXX Exemption Request: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-XXX) 1.0 Purpose Southern Nuclear Operating Company (the Licensee) requests a permanent exemption from the provisions of 10 CFR 52, Appendix D, Section III.B, Design Certification Rule for the AP1000 Design, Scope and Contents, to allow a departure from elements of the certification information in Tier 1 of the generic AP1000 Design Control Document (DCD).

The regulation, 10 CFR 52, Appendix D, Section III.B, requires an applicant or licensee referencing Appendix D to 10 CFR Part 52 to incorporate by reference and comply with the requirements of Appendix D, including certified information in DCD Tier 1.

This request for exemption provides the technical and regulatory basis to demonstrate that 10 CFR 52.63, §52.7, and §50.12 requirements are met and will apply the requirements of 10 CFR 52, Appendix D, Section VIII.A.4 to allow departures epart eparture from generic Tier 1 Inspections, Tests, Analyses, and Acceptance Criteria (ITAA (ITAAC) information infor to modify the seismic gap requirements above grade between the nuclear uclear island islan and tthe adjacent annex nd J from El. 141 building/turbine building between Column Lines I and 141 through throug El. 154 in the 2.0 Electric Generating Plant (VEGP) Unit 3.

Background

T built localized nonconform licensing basis to accommodate construction as-built noncon nonconformances at Vogtle requirements above grade tables which support the AF The Licensee is the holder of Combined and operation of a Westinghouse ed License No. NPF-91, e Electric evis VEGP NPF ectric Company AP1000 Unit 3. The proposed changes would revise AP10 AP1 w

which authorizes construction nuclear plant named VEGP VEGP Unit 3 ITAAC affecting the seismic gap e between the nuclear island and the adjacent annex reque building/turbine building. This activity requests e associated COL Appendix App Append ex exemption C ITAAC.

from the Generic DCD Tier 1 3.0 R

An exemption from elements 3.00.13.

3.00.13 ITAAC No. 3.3.00.13.

ents of the AP1000 certified plant--spe plant Technical Justification of Accep A

depa Acceptability c

specific departures to allow VEGP Unit 3 plant-specific (Tier 1) design information is requested to be taken from the VEGP Unit 3 Tier 1 D hanges would revise the VEGP Unit 3 COL and licensing basis documents The proposed changes smic gap requirements above grade between the nuclear island and to modify the seismic x bu portions of the annex building and turbine building first bay adjacent to the nuclear island.

Currently, the requirement in the licensing basis for the minimum gap between the nuclear island and annex building/turbine building is 3 inches, as specified in COL Appendix C ITAAC No. 3.3.00.13, UFSAR Appendix 2.5E Section 5.2, and UFSAR Subsections 3.7.2.8.1 and 3.8.5.1. UFSAR Subsection 3.8.5.1 requires that a minimum 1-inch gap be maintained between the nuclear island and annex building/turbine building considering the displacements of the buildings during the safe shutdown earthquake (SSE) events. The purpose of the licensing basis requirements is to ensure there is no interaction between the nuclear island and annex building/turbine building during SSE events.

The proposed changes reduce the minimum gap requirements for VEGP Unit 3 between the nuclear island and the annex building/turbine building between Column Lines I and J from El. 141 through El. 154 to 2-1/16 inches (to bound the nonconforming measured Page 2 of 7

ND-20-XXXX Exemption Request: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-XXX) minimum gap of 2-3/16 inches in this localized area) which leaves at least a 1-inch gap between the nuclear island and the annex building/turbine building during a seismic event.

The proposed changes to the VEGP Unit 3 gap requirements do not reduce the 1-inch gap margin in a seismic event, as identified in UFSAR Subsection 3.8.5.1. The proposed changes to the gap requirements do not affect the structural integrity requirements on seismic Category I structures. The safety functions of the seismic Category I structures are not impacted. The performance of the seismic Category II structures is not impacted and does not degrade the function of a seismic Category I structure, system or component (SSC).

Detailed technical justification supporting this request for exemption is provided in Section 2 of the associated License Amendment Request in Enclosure 1 of o this letter.

4.0 Justification of Exemption 10 CFR Part 52, Appendix D, Section VIII.A.4 and 10 0 CFR 52.63(b)(1) 52.63(b) govgovern the issuance discussed in Enclosure 1 of the accompanying T of exemptions from elements of the certified design ng ign information for AP100 plants. Since SNC has identified changes to the Tier 1 information g License Amendment er 1 iss needed.

from the certified design information in Tier Am A

AP1000 nuclear power ion fo R

ffor VEGP Unit 3 as Request, an exemption AF 10 CFR Part 52, Appendix D, and 10 CFR 50.12, §52.7, a grant exemptions from the requirements undue risk to the health and safety ements with the common defense and security [§50.12(a)(1 from the reduction in

[§50.1

[§50.12

[§50.12(a)(1)];

ecial circumstances outweigh

[§50.12(a)(2)]; 5) the special outwe ou

§5 and §52.63 state that the NRC may nts of the regulations provided six conditions are met:

1) the exemption is authorized by law [§50.12(a)(1)]; 2) 2 the exemption will not present an afety of the public [§50.12(a)(1)]; 3) the exemption is consistent

4) special circumstances are present any decrease in safety that may result n standardization caused by the exemption [§52.63(b)(1)]; and 6) the VIII.A.4].

The requested below.

R esult in changes do not result n a significant dec sted exemption satisfies the decrease in the level of safety [Part 52, App. D, th criteria for granting specific exemptions, as described D on is author

1. This exemption authorized by law ority under 10 CFR 52.63, §52.7, and §50.12 to grant exemptions from The NRC has authority the requirements of NRC regulations. Specifically, 10 CFR 50.12 and §52.7 state that the NRC may grant exemptions from the requirements of 10 CFR Part 52 upon a proper showing. No law exists that would preclude the changes covered by this exemption request. Additionally, granting of the proposed exemption does not result in a violation of the Atomic Energy Act of 1954, as amended, or the Commissions regulations.

Accordingly, this requested exemption is authorized by law, as required by 10 CFR 50.12(a)(1).

Page 3 of 7

ND-20-XXXX Exemption Request: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-XXX)

2. This exemption will not present an undue risk to the health and safety of the public The proposed exemption from the requirements of 10 CFR 52, Appendix D, Section III.B would allow changes to elements of the VEGP Unit 3 plant-specific Tier 1 DCD to depart from the AP1000 certified (Tier 1) design information. The VEGP Unit 3 plant-specific DCD Tier 1 will continue to reflect the approved licensing basis for VEGP Unit 3 and will maintain a consistent level of detail with that which is currently provided elsewhere in Tier 1 of the DCD. Therefore, the affected VEGP Unit 3 plant-specific DCD Tier 1 ITAAC will continue to serve its required purpose.

The proposed changes would revise the VEGP Unit 3 plant-specific Tier 1 information to modify the seismic gap requirements above grade between the he nuclear n island and portions ent to th of the annex building and turbine building first bay adjacent the nuclear island. These changes do not introduce any new industrial, chemical,, or radiological rad radiologica hazards that would represent a public health or safety risk, nor do they modify or re remove an any design controls, ex operational controls, or safeguards intended to mitigate any existing o on-site hazards.

Furthermore, the proposed changes would not T ot allow for a new fission ailures ures. Accordingly, events that would result in fuel cladding failures. ccordi posed equipment an undue risk from any existing or proposed th the equipme or systems.

syste fis product release path, result in a new fission product barrierr failure mode, or create a new sequence of e cchanges do not present The requested exemption AF Therefore, the requested exemption nsee on n from 10 CFR 52, A tent with the common defense

3. The exemption is consistent de tion from the requirements see to depart from elements would allow the licensee requirem elem Appen Appendix D,Section III.B would not alth and safety of the pub present an undue risk to the health public.

and security requirement of 10 CFR 52, Appendix D, Section III.B of the VEGP Unit 3 plant-specific DCD R ormation on.. The proposed exemption Tier 1 design information.

us of the plant.

secure status plant The proposed ds procedures.

safeguards p

prop ex ny structures or plant equipment operation of any equ does not alter the design, function, or that is necessary to maintain a safe and exemption has no impact on plant security or D he requested ex Therefore, the exem exemption is consistent with the common defense and security.

stances are present

4. Special circumstances 10 CFR 50.12(a)(2) lists six special circumstances for which an exemption may be granted. Pursuant to the regulation, it is necessary for one of these special circumstances to be present in order for the NRC to consider granting an exemption request. The requested exemption meets the special circumstances of 10 CFR 50.12(a)(2)(ii). That subsection defines special circumstances as when Application of the regulation in the particular circumstances would not serve the underlying purpose of the rule or is not necessary to achieve the underlying purpose of the rule.

The rule under consideration in this request for exemption is 10 CFR 52, Appendix D, Section III.B, which requires that a licensee referencing the AP1000 Design Certification Rule (10 CFR Part 52, Appendix D) shall incorporate by reference and comply with the requirements of Appendix D, including Tier 1 information. The VEGP Unit 3 COL references the AP1000 Design Certification Rule and incorporates by reference the Page 4 of 7

ND-20-XXXX Exemption Request: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-XXX) requirements of 10 CFR Part 52, Appendix D, including Tier 1 information. The underlying purpose of Appendix D,Section III.B is to describe and define the scope and contents of the AP1000 design certification, and to require compliance with the design certification information in Appendix D.

The proposed exemption would modify the seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island. The proposed changes do not affect any function or feature used for the prevention and mitigation of accidents or their safety analyses. No safety-related SSC or function is involved. The proposed changes do not involve nor interface with any SSC accident initiator or initiating sequence of events related to the accidents evaluated and therefore do not have an adverse e effect eff ef on any SSCs design ation information function. Accordingly, this exemption from the certification infor will enable the Licensee to safely construct and operate the AP1000 0 facility consistent consis with the design certified by the NRC in 10 CFR 52, Appendix D.

the underlying purpose of the rule.

T ussed beca Therefore, special circumstances are present, because sed in this request III.B, in the particular circumstances discussed req ation o application is no A

th current generic of the ired by 10 CFR Part 52, Appendix certified design information in Tier 1 as required D, Section not necessary to achieve AF

5. The special circumstances outweigh the reduction in standardization Based on the nature of the eigh any decrease in safety weigh on caused e changes to the VEGP U and the understanding that these changes change support island and portions off the annex building and supp nuclear island, it iss expected that this exemption exem s

exemption.

aused by the exe exemm that may result from Unit 3 plant-specific Tier 1 information the design function of the nuclear a turbine building first bay adjacent to the may be requested by other AP1000 R

licensees and applicants.

from the departure and applicants to outweigh ts.. However, a review pplicants rture from the standard stan ants do not request this same rev DCD of the reduction in standardization resulting DC determined that even if other AP1000 licensees sam departure, the special circumstances will continue gh any decrease in safety from the reduction in standardization because the key design functions nctions of the structures st struc associated with this request will continue to be D

maintained. Furthermore, the ption request and this exemption limited change from t justification provided in the License Amendment Request reque and the associated mark-ups demonstrate that there is a m the standard information provided in the generic AP1000 DCD, which is offset by the special circumstances identified above.

Therefore, the special circumstances associated with the requested exemption outweigh any decrease in safety that may result from the reduction in standardization caused by the exemption.

6. The design change will not result in a significant decrease in the level of safety.

The exemption revises the VEGP Unit 3 plant-specific DCD Tier 1 information by revising the seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island as discussed in Section 2.0. The changes to the seismic gap requirements do not change the design requirements for the nuclear island and portions of the annex building and turbine building Page 5 of 7

ND-20-XXXX Exemption Request: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-XXX) first bay adjacent to the nuclear island. Because these functions continue to be met, there is no reduction in the level of safety.

5.0 Risk Assessment A risk assessment was not determined to be applicable to address the acceptability of this proposal.

6.0 Precedent Exemptions None 7.0 Environmental Consideration The Licensee requests a departure from elements of the certifiedcer inf information in Tier 1 of the generic AP1000 DCD. The Licensee has determined ermined rmined that the proposed pr departure equirements of 1 would require a permanent exemption from the requirements 10 CFR 52, Appendix D, defined in 10 CFR Part 20, or which changes T Section III.B, Design Certification Rule for the AP1000 Design, Scope a however, the Licensee evaluation of the proposed ponents located within the restricted area, as respect to installation or use of facility components ges es an inspection inspection spect or a su posed exemption e

and Contents, with surveillance requirement; has determined that the 10 CFR 51.22(c)(9).

AF significant change in the may be released offsite, ation occupational radiation gibility criteria for categorical proposed exemption meets the eligibility Based on the above review of the proposed the proposed activity does posed exemption e types or significant increase ffsite, n exposure significa incre fsite, or (iii) a significant catego exclusion set forth in exemption, the Licensee has determined that es not involve (i) a significant sign hazards consideration, (ii) a in the amounts of any effluents that significan increase in the individual or cumulative exposure.. Accordingly, Accordingl the proposed exemption meets the eligibility R

criteria for categorical CFR 51.22(b),

gorical orical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 b), an environmenta environmental impa proposed exemption is not requirerequired impact statement or environmental assessment of the required.

8.0 D

Conclusion etails of the environmental Specific details enviro environm are provided in Section 5 of his letter.

Enclosure 1 of this considerations supporting this request for exemption o the associated License Amendment Request provided in The proposed changes to VEGP Unit 3 Tier 1 seismic gap requirements above grade between the nuclear island and portions of the annex building and turbine building first bay adjacent to the nuclear island are necessary to accommodate construction as-built localized nonconformances at VEGP Unit 3. The exemption request meets the requirements of 10 CFR 52.63, Finality of design certifications, 10 CFR 52.7, Specific exemptions, 10 CFR 50.12, Specific exemptions, and 10 CFR 52 Appendix D, Design Certification Rule for the AP1000. Specifically, the exemption request meets the criteria of 10 CFR 50.12(a)(1) in that the request is authorized by law, presents no undue risk to public health and safety, and is consistent with the common defense and security.

Furthermore, approval of this request does not result in a significant decrease in the level of safety, satisfies the underlying purpose of the AP1000 Design Certification Rule, and Page 6 of 7

ND-20-XXXX Exemption Request: Unit 3 Auxiliary Building Wall 11 Seismic Gap Requirements (LAR-20-XXX) does not present a significant decrease in safety as a result of a reduction in standardization.

9.0 References None T

AF R

D Page 7 of 7

Southern Nuclear Operating Company ND-20-XXXX Enclosure 3 T

Vogtle Electric Generating Plant EG Unit 3 Plan (VEGP)

AF Proposed Changes nges to Licensing Basi Basis Documents (LAR-20-001)

((LAR-20 20-001)

R D Note:

Added text is shown as bold Blue Underline Deleted text is shown as bold Red Strikethrough Omitted text is shown as bold * * *

(Enclosure 3 consists of 5 pages, including this cover page)

ND-20-XXXX Enclosure 3 Proposed Changes to Licensing Basis Documents (LAR-20-XXX)

VEGP Unit 3 COL Appendix C (and VEGP Unit 3 Plant-Specific Tier 1) Table 3.3-6 is revised as follows:

Table 3.3-6 Inspections, Tests, Analyses, and Acceptance Criteria No. ITAAC No. Design Commitment Inspections, Tests, Analyses Acceptance Criteria 819 3.3.00.13 13. Separation is provided between the An inspection of the separation epar epara The minimum horizontal structural elements of the turbine and of the nuclear island d from the clearance above floor annex buildings and the nuclear island annex and turbine ne building build elevation 100-0 between the structure. This separation permits structures willl be performed performed.

performe . structural elements of the horizontal motion of the buildings in The inspection tion will verify the annex building and the nuclear an the safe shutdown earthquake without impact between structural elements of the buildings.

T specified between consisting d horizontal clearance een structural elements of thee adjacent buildin buildings, sisting of the reinforced concrete ete walls and slabs, structural steel columns and floor beams.

island is 3 inches; except that isl the minimum horizontal clearance between elevations 141 0 and 154 0 between structural elements of the annex building and the nuclear island between column lines I and J is 2-1/16 inches. The minimum RA horizontal clearance above floor elevation 100-0 between the structural elements of the turbine building and the nuclear island is 3 inches; except that the minimum horizontal clearance between elevations 141 0 and 154 0 between structural elements of the turbine building and the nuclear island between column lines I and J is 2-1/16 inches.

Page 2 of 5

ND-20-XXXX Proposed Changes to Licensing Basis Documents (LAR-20-XXX)

UFSAR Appendix 2.5E, AP1000 Site Specific Seismic Evaluation Report, Section 5.2, is revised as follows:

5.2 Adjacent Building Seismic Demand

• *

• The maximum relative displacement between nuclear island and at top of the Annex building for the ESP Best Estimate soil case is 2, which is less than the 3 inch minimum gap between nuclear island and annex building and which is less than the 2-1/16 inches minimum gap at Unit 3 between nuclear island and annex building between elevations 141'-0" and 154'-0" between column lines I and J. * *

• T AF R

D Page 3 of 5

ND-20-XXXX Proposed Changes to Licensing Basis Documents (LAR-20-XXX)

UFSAR Subsection 3.7.2.8.1, Annex Building, is revised as follows:

3.7.2.8.1 Annex Building The minimum space required between the annex building and the nuclear island to avoid contact is obtained by absolute summation of the deflections of each structure obtained from either a time history or a response spectrum analysis for each structure. The maximum displacement of the roof of the annex building is 1.6 inches in the east-west ast direction. The minimum clearance between the structural elements of the annex x building buildin build above grade and the nuclear island is 3 inches; except that the minimum clearance ce at Unit 3 between elevations 141'-0" and 154'-0" between structural elements of the annex nnex building bui an and the nuclear island between column lines I and J is 2-1/16 inches.

AF T

R D

Page 4 of 5

ND-20-XXXX Proposed Changes to Licensing Basis Documents (LAR-20-XXX)

UFSAR Subsection 3.8.5.1, Description of the Foundations, is revised as follows:

3.8.5.1 Description of the Foundations

[The turbine building and annex building are structurally separated from the nuclear island structures by a 2-inch gap at and below the grade. A 3-inch minimum gap is provided above grade; except that the minimum gap for Unit 3 between elevations 141'-0" and 154'-0" between column lines I and J is 2-1/16 inches.]* * *

• Page 5 of 5